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European Journal of Cell Biology Jun 2023The study of endomembrane trafficking is crucial for understanding how cells and whole organisms function. Moreover, there is a special interest in investigating... (Review)
Review
The study of endomembrane trafficking is crucial for understanding how cells and whole organisms function. Moreover, there is a special interest in investigating endomembrane trafficking in plants, given its role in transport and accumulation of seed storage proteins and in secretion of cell wall material, arguably the two most essential commodities obtained from crops. The mechanisms of anterograde transport in the biosynthetic and endocytic pathways of plants have been thoroughly discussed in recent reviews, but, comparatively, retrograde trafficking pathways have received less attention. Retrograde trafficking is essential to recover membranes, retrieve proteins that have escaped from their intended localization, maintain homeostasis in maturing compartments, and recycle trafficking machinery for its reuse in anterograde transport reactions. Here, we review the current understanding on retrograde trafficking pathways in the endomembrane system of plants, discussing their integration with anterograde transport routes, describing conserved and plant-specific retrieval mechanisms at play, highlighting contentious issues and identifying open questions for future research.
Topics: Biological Transport; Plants; Protein Transport
PubMed: 36933283
DOI: 10.1016/j.ejcb.2023.151309 -
Annals of Botany Oct 2003Calcium is an essential plant nutrient. It is required for various structural roles in the cell wall and membranes, it is a counter-cation for inorganic and organic... (Review)
Review
Calcium is an essential plant nutrient. It is required for various structural roles in the cell wall and membranes, it is a counter-cation for inorganic and organic anions in the vacuole, and the cytosolic Ca2+ concentration ([Ca2+]cyt) is an obligate intracellular messenger coordinating responses to numerous developmental cues and environmental challenges. This article provides an overview of the nutritional requirements of different plants for Ca, and how this impacts on natural flora and the Ca content of crops. It also reviews recent work on (a) the mechanisms of Ca2+ transport across cellular membranes, (b) understanding the origins and specificity of [Ca2+]cyt signals and (c) characterizing the cellular [Ca2+]cyt-sensors (such as calmodulin, calcineurin B-like proteins and calcium-dependent protein kinases) that allow plant cells to respond appropriately to [Ca2+]cyt signals.
Topics: Biological Transport; Calcium; Calcium Channels; Calcium Signaling; Models, Biological; Plants
PubMed: 12933363
DOI: 10.1093/aob/mcg164 -
ChemPlusChem Nov 2022The development of synthetic anion transporters is motivated by their potential application as treatment for diseases that originate from deficient anion transport by... (Review)
Review
The development of synthetic anion transporters is motivated by their potential application as treatment for diseases that originate from deficient anion transport by natural proteins. Transport of bicarbonate is important for crucial biological functions such as respiration and digestion. Despite this biological relevance, bicarbonate transport has not been as widely studied as chloride transport. Herein we present an overview of the synthetic receptors that have been studied as bicarbonate transporters, together with the different assays used to perform transport studies in large unilamellar vesicles. We highlight the most active transporters and comment on the nature of the functional groups present in active and inactive compounds. We also address recent mechanistic studies that have revealed different processes that can lead to net transport of bicarbonate, as well as studies reported in cells and tissues, and comment on the key challenges for the further development of bicarbonate transporters.
Topics: Bicarbonates; Biological Transport; Ion Transport
PubMed: 36414387
DOI: 10.1002/cplu.202200266 -
Annual Review of Physiology Feb 2023Numerous trafficking and quality control pathways evolved to handle the diversity of proteins made by eukaryotic cells. However, at every step along the biosynthetic... (Review)
Review
Numerous trafficking and quality control pathways evolved to handle the diversity of proteins made by eukaryotic cells. However, at every step along the biosynthetic pathway, there is the potential for quality control system failure. This review focuses on the mechanisms of disrupted proteostasis. Inspired by diseases caused by misfolded proteins in the kidney (mucin 1 and uromodulin), we outline the general principles of protein biosynthesis, delineate the recognition and degradation pathways targeting misfolded proteins, and discuss the role of cargo receptors in protein trafficking and lipid homeostasis. We also discuss technical approaches including live-cell fluorescent microscopy, chemical screens to elucidate trafficking mechanisms, multiplexed single-cell CRISPR screening platforms to systematically delineate mechanisms of proteostasis, and the advancement of novel tools to degrade secretory and membrane-associated proteins. By focusing on components of trafficking that go awry, we highlight ongoing efforts to understand fundamental mechanisms of disrupted proteostasis and implications for the treatment of human proteinopathies.
Topics: Humans; Protein Transport; Kidney; Biological Transport; Homeostasis
PubMed: 36763970
DOI: 10.1146/annurev-physiol-031522-100639 -
Annual Review of Cell and Developmental... Oct 2023The life of eukaryotic cells requires the transport of lipids between membranes, which are separated by the aqueous environment of the cytosol. Vesicle-mediated traffic... (Review)
Review
The life of eukaryotic cells requires the transport of lipids between membranes, which are separated by the aqueous environment of the cytosol. Vesicle-mediated traffic along the secretory and endocytic pathways and lipid transfer proteins (LTPs) cooperate in this transport. Until recently, known LTPs were shown to carry one or a few lipids at a time and were thought to mediate transport by shuttle-like mechanisms. Over the last few years, a new family of LTPs has been discovered that is defined by a repeating β-groove (RBG) rod-like structure with a hydrophobic channel running along their entire length. This structure and the localization of these proteins at membrane contact sites suggest a bridge-like mechanism of lipid transport. Mutations in some of these proteins result in neurodegenerative and developmental disorders. Here we review the known properties and well-established or putative physiological roles of these proteins, and we highlight the many questions that remain open about their functions.
Topics: Carrier Proteins; Proteins; Biological Transport; Cell Membrane; Lipids
PubMed: 37406299
DOI: 10.1146/annurev-cellbio-120420-014634 -
Annals of the New York Academy of... Jan 2020Most clinical antibiotics do not have efficacy against Gram-negative pathogens, mainly because these cells are protected by the permeability barrier comprising the two... (Review)
Review
Most clinical antibiotics do not have efficacy against Gram-negative pathogens, mainly because these cells are protected by the permeability barrier comprising the two membranes with active efflux. The emergence of multidrug-resistant Gram-negative strains threatens the utility even of last resort therapeutic treatments. Significant efforts at different levels of resolution are currently focused on finding a solution to this nonpermeation problem and developing new approaches to the optimization of drug activities against multidrug-resistant pathogens. The exceptional efficiency of the Gram-negative permeability barrier is the result of a complex interplay between the two opposing fluxes of drugs across the two membranes. In this review, we describe the current state of understanding of the problem and the recent advances in theoretical and empirical approaches to characterization of drug permeation and active efflux in Gram-negative bacteria.
Topics: Animals; Anti-Bacterial Agents; Biological Transport; Drug Resistance, Multiple, Bacterial; Gram-Negative Bacteria; Humans; Permeability
PubMed: 31165502
DOI: 10.1111/nyas.14134 -
Cells Feb 2021Intracellular organelles enwrapped in membranes along with a complex network of vesicles trafficking in, out and inside the cellular environment are one of the main... (Review)
Review
Intracellular organelles enwrapped in membranes along with a complex network of vesicles trafficking in, out and inside the cellular environment are one of the main features of eukaryotic cells. Given their central role in cell life, compartmentalization and mechanisms allowing their maintenance despite continuous crosstalk among different organelles have been deeply investigated over the past years. Here, we review the multiple functions exerted by the endosomal sorting complex required for transport (ESCRT) machinery in driving membrane remodeling and fission, as well as in repairing physiological and pathological membrane damages. In this way, ESCRT machinery enables different fundamental cellular processes, such as cell cytokinesis, biogenesis of organelles and vesicles, maintenance of nuclear-cytoplasmic compartmentalization, endolysosomal activity. Furthermore, we discuss some examples of how viruses, as obligate intracellular parasites, have evolved to hijack the ESCRT machinery or part of it to execute/optimize their replication cycle/infection. A special emphasis is given to the herpes simplex virus type 1 (HSV-1) interaction with the ESCRT proteins, considering the peculiarities of this interplay and the need for HSV-1 to cross both the nuclear-cytoplasmic and the cytoplasmic-extracellular environment compartmentalization to egress from infected cells.
Topics: Biological Transport; Cells; Endosomal Sorting Complexes Required for Transport; Humans; Viruses
PubMed: 33668191
DOI: 10.3390/cells10030483 -
Molecular Plant Aug 2017Plants employ sophisticated mechanisms to interact with pathogenic as well as beneficial microbes. Of those, membrane trafficking is key in establishing a rapid and... (Review)
Review
Plants employ sophisticated mechanisms to interact with pathogenic as well as beneficial microbes. Of those, membrane trafficking is key in establishing a rapid and precise response. Upon interaction with pathogenic microbes, surface-localized immune receptors undergo endocytosis for signal transduction and activity regulation while cell wall components, antimicrobial compounds, and defense proteins are delivered to pathogen invasion sites through polarized secretion. To sustain mutualistic associations, host cells also reprogram the membrane trafficking system to accommodate invasive structures of symbiotic microbes. Here, we provide an analysis of recent advances in understanding the roles of secretory and endocytic membrane trafficking pathways in plant immune activation. We also discuss strategies deployed by adapted microbes to manipulate these pathways to subvert or inhibit plant defense.
Topics: Biological Transport; Cell Membrane; Endocytosis; Plant Immunity
PubMed: 28698057
DOI: 10.1016/j.molp.2017.07.001 -
Cold Spring Harbor Perspectives in... Oct 2012The transport of lipids from their synthesis site at the endoplasmic reticulum (ER) to different target membranes could be mediated by both vesicular and nonvesicular... (Review)
Review
The transport of lipids from their synthesis site at the endoplasmic reticulum (ER) to different target membranes could be mediated by both vesicular and nonvesicular transport mechanisms. Nonvesicular lipid transport appears to be the major transport route of certain lipid species, and could be mediated by either spontaneous lipid transport or by lipid-transfer proteins (LTPs). Although nonvesicular lipid transport has been extensively studied for more than four decades, its underlying mechanism, advantage and regulation, have not been fully explored. In particular, the function of LTPs and their involvement in intracellular lipid movement remain largely controversial. In this article, we describe the pathways by which lipids are synthesized at the ER and delivered to different cellular membranes, and discuss the role of LTPs in lipid transport both in vitro and in intact cells.
Topics: Biological Transport; Carrier Proteins; Cell Membrane; Endoplasmic Reticulum; Lipid Metabolism; Lipids; Models, Biological
PubMed: 23028121
DOI: 10.1101/cshperspect.a013300 -
Trends in Endocrinology and Metabolism:... Apr 2012Although lipid metabolism and host defense are widely considered to be very divergent disciplines, compelling evidence suggests that host cell handling of self- and... (Review)
Review
Although lipid metabolism and host defense are widely considered to be very divergent disciplines, compelling evidence suggests that host cell handling of self- and microbe-derived (e.g. lipopolysaccharide, LPS) lipids may have common evolutionary roots, and that they indeed may be inseparable processes. The innate immune response and the homeostatic network controlling cellular sterol levels are now known to regulate each other reciprocally, with important implications for several common diseases, including atherosclerosis. In the present review we discuss recent discoveries that provide new insight into the bidirectional crosstalk between reverse cholesterol transport and innate immunity, and highlight the broader implications of these findings for the development of therapeutics.
Topics: Animals; Biological Transport; Cholesterol; Humans; Immunity, Innate; Models, Biological
PubMed: 22406271
DOI: 10.1016/j.tem.2012.02.001